Species catalogue of Drymaeus (Mesembrinus) Alberts, 1850 (Gastropoda: Bulimulidae) from Brazil and new data on morphology and distribution of Drymaeus (Mesembrinus) interpunctus (Martens, 1887)

Background Herein, we attempted to obtain detailed data on the distribution of the species of Drymaeus (Mesembrinus) in Brazil, using biodiversity databases, malacological collections and literature as sources of occurrence records. We provided a catalogue of species, along with distribution maps. We also estimated the suitable distribution of Drymaeus (Mesembrinus) interpunctus using the maximum entropy approach. A detailed description of the anatomy of the soft parts of this species was provided, with new data on the pallial system. Materials and Methods For each species we provided information on the compiled data associated with museum collections and the literature. Distribution maps including geographic boundaries, Brazilian biomes and altitude were made with QGIS software 3.16.10 Hannover. For niche modelling, nineteen bioclimatic variables and a topographic variable were used as predictors. The models were performed with MaxEnt version 3.3.3k. Results Most of the species are represented by scarce material in malacological collections; for some species, these records correspond to type material, indicating that they have not been recollected. Most of the species were represented by shells making anatomical comparison and DNA analysis difficult, limiting our ability to provide new criteria for species delimitation. Our results allowed us to expand the known distribution area for three species, Drymaeus dutaillyi, D. gereti and D. oreades, with new occurrence records in Brazil. The MaxEnt model showed a thin area of high suitability to D. (M.) interpunctus in the Southeastern Brazil, corresponding to the Atlantic Forest. Minimum temperature of the coldest month and mean temperature of coldest quarter were the variables that most influenced the development of the model. Discussion Drymaeus interpunctus was described based on specimens collected in Brazil without mention to the exact localities. Herein the new records from databases allowed to expand the known geographic distribution for this species and to infer its potential distribution. Although the type locality of D. interpunctus is in Brazil, the anatomy of the soft parts of specimens from this country was not previously described. The anatomy of the reproductive system of the specimens analyzed herein mostly corresponds to a previous description for specimens from Paraguay, except for the absence of penial sheath and the relative length of the bursa copulatrix duct. The results of niche modeling showed a thin area of high suitability for D. interpunctus and a vast area of moderate suitability, indicating that this species present a niche breadth that favors its occurrence in a range of different biomes, including less suitable areas. Conclusion The small number of records obtained for most of the species and their restricted ranges associated with habitat destruction may indicate that they are of conservation concern.

Drymaeus (Albers, 1850) is one of the most species-rich bulimulid genera occurring in Brazil, with approximately 55 species (Simone, 2006;Salvador, Cavallari & Simone, 2015;Simone & Amaral, 2018). This genus comprises two subgenera, Drymaeus and Mesembrinus (Albers, 1850). The species ascribed to the subgenus Mesembrinus are distributed in Central America, South America, and Caribbean. Originally, Mesembrinus was proposed as subgenus of Bulimus (type species: Helix (Cochlogena) virgulata Férussac, 1821). The diagnosis of the subgenus was provided by Albers (1850), and it was originally based on shell characteristics. Pilsbry (1898) considered Drymaeus as a genus and Mesembrinus as a subgenus, based on shell morphological characteristics. Accordingly, species of the subgenus Mesembrinus are characterized by shells with unexpanded, simple outer lips and those from the subgenus Drymaeus are characterized by shells with expanded or reflected lips. Breure (1979) added other traits for the differentiation of the two subgenera (i.e.: numbers of plates in the jaw and morphology of the radular teeth). The subgenus Mesembrinus is characterized by a peristome usually simple, a jaw with more than 20

Morphological characterization
The specimens of D. (Mesembrinus) interpunctus were killed and fixed according to Thomé & Lopes (1973), then dissected immersed in ethanol and drawn under a stereo-microscope Olympus ® , model SZX7 equipped with a drawing tube. All structures of the reproductive and pallial systems were drawn and photographed. Details of the shell were acquired through scanning electron microscopy. The shell was mounted, without any preparation, on a stub covered with adhesive tape of carbon and imaged in a Hitachi low vacuum tabletop scanning electron microscope, model TM3000. The identification of D. (Mesembrinus) interpunctus was based on the species original description (Albers, 1850) as well as on Breure (1979), , and Simone (2006).

Data collection
To provide an annotated checklist of the species of the genus Drymaeus, subgenus Mesembrinus, an intensive research was performed using data from the literature, malacological collections' databases and data portals as Global Biodiversity Information Facility, Sys Tax-Zoological Collections and SpeciesLink (GBIF, 2020;SpeciesLink, 2020;SysTax, 2020). We also included records from the malacological collection of Museu de Zoologia da Universidade de São Paulo kindly provided by the curator. All museum deposition numbers are provided in the checklist, including information on type material. The material analyzed in person by the authors are labelled as ''material examined'', additionally a list of museum deposits ascribed to each species is provided in the topic ''museum deposits'', with the objective of facilitate future studies on taxonomy and morphology of Drymaeus (Mesembrinus) species. To provide a provisional characterization of the geographic distribution of these poorly known species, we compile and critically analyze all the occurrence records obtained through an intensive search in the literature, biodiversity databases, and malacological collections. We considered species identification in literature records as valid when it felt in the known distribution area of the species. Concerning the occurrence records obtained via malacological collections, in some cases we were able to validate species identification using shell morphological criteria currently accepted, because the images of these specimens were available in the databases, they were ceded by the curators of the collections, or we had the chance to analyze the specimens personally. Nonetheless, for some of the records herein compiled we could not validate species labelling. Thus, we discriminated occurrence records for which species identity was confirmed and occurrence records without confirmation of species identity (Table S1). Accordingly, the generated maps allow to critically consider the known distribution of the species. Discrepant occurrence records falling outside the known range of a species were not included in the maps.
For distribution maps, localities of occurrence of the species were georeferenced with Google Earth Pro (https://www.google.com.br/earth/) and GeoLocate application (https://www.geo-locate.org/). The duplicated points and occurrence records without specific localities were excluded from the analysis. The maps were made with QGIS software 3.16.10 Hannover (QGIS Development Team, 2021), and included geographic boundaries, ecoregions and altitude information, obtained from the Brazilian Institute of Geography and Statistics (IBGE: https://www.ibge.gov.br/geociencias/downloads-geociencias.html).
We provided information on the compiled data associated to the museum deposits (i.e.: mode of preservation, number of specimens, collection date, and locality), and from the literature (illustrations and occurrence records). The type locality for each species is given in quotation marks as it is stated in the original publication and in the same language used by the author. The type material of each species have been searched consulting the material housed in different collections (photos, original labels) as well as by consulting of the relevant bibliography (Breure, 1979;Breure & Ablett, 2014). We compiled a total of 95 geographic records of Drymaeus (Mesembrinus) interpunctus from museum collections, and scientific articles used in the Ecological Niche Analysis (Table S1). Taxonomic bibliography were obtained mostly from the Biodiversity Heritage Library website (BHL, 2019).

Ecological niche models
Nineteen bioclimatic variables and a topographic variable (altitude), at a spatial resolution of 30 arc seconds (∼1 km 2 ), were used as predictors. These data were obtained from WorldClim (http://www.worldclim.org). We clipped the environmental data layers to the calibration area defined as South America. The models were performed with the software package MaxEnt version 3.3.3k (Phillips, Anderson & Schapire, 2006). The default parameters of MaxEnt algorithm were used, including a maximum of 500 iterations with a convergence threshold of 0.00001 and 10,000 randomly chosen background localities. 100 replicates were run, and a random test percentage option was used with 75% of presence records randomly selected to generate the models, while the remaining 25% was used to test them. The model was computed as ''logistic''. This output returns a continuous map with an estimated probability of presence between 0 (no probability of the species presence) and 1 (high probability of presence), which permits fine distinctions between the suitability of different areas modeled (Giovanelli et al., 2008). For each model, the performance was assessed using the method of the area under the curve (AUC) of the receiver operating characteristic (ROC). The AUC represents the probability for the model to score a presence site (test locality) higher than a random background site (Phillips, Anderson & Schapire, 2006;Elith et al., 2006).

Annotated checklist of species of Drymaeus, subgenus Mesembrinus from Brazil
A total of 196 occurrence records of seven species of Drymaeus, subgenus Mesembrinus were compiled for Brazil (Table S1, Fig. 1). Most of the species are represented in malacological collections from North America and Europe (Fig. 2). In some cases, these records correspond only to the type material, ie.: Drymaeus (Mesembrinus) dutaillyi with two records including the lectotype and Drymaeus (Mesembrinus) lynchi with four records, including the holotype and paratype, both in North and South American collections (Fig. 2). Some species whose records in Brazil are uncertain, i.    Distribution: Argentina (Parodiz, 1957;Miquel, 1991); Paraguay (Bertoni, 1926;Schade, 1965); Uruguay (Ihering, 1923;Parodiz, 1957). In Brazil, the occurrence records from the literature correspond to localities at Rio de Janeiro (one record), Paraná (three records), Rio Grande do Sul (18) and São Paulo (29) states. The occurrence records for this species correspond to four of the six, biomes from Brazil. The Atlantic Forest was the biome with the highest number of records (Fig. 3). We found one record for Bolivia: Santa Cruz, Buena Vista; Mar 1951; MLP 8570. But after checking the image of the specimen, we confirmed that this is a case of misidentification. Potential distribution: AUC calculated from the ROC curve generated for Maxent was 0.932 with a standard deviation of 0.010. The MaxEnt model showed a thin area of high suitability to Drymaeus (Mesembrinus) interpunctus in the southeastern region of Brazil (Fig. 4). This area coincides with the Atlantic Forest biome in the states of Rio de Janeiro, São Paulo, Paraná, and Santa Catarina. The jackknife test of variable importance in MaxEnt showed that Minimum temperature of the coldest month (BIO6) and mean temperature of coldest quarter (BIO11) were the variables that most influenced the development of the model when these variables were used alone (Fig. S1).

Morphological description
Shell (Fig. 5): Shell perforate, conic-oblong, thin, very spirally striated; whitish to pale yellow, with widely separated vertical series of brown spots, and two bands on the shell base (Figs. 5A-5C, 5F). Protoconch with a grating sculpture formed by axial riblets and spiral striae (Figs. 5D, 5E). Shell surface smooth with regular and shallow striae. Seven whorls, nearly flat, body whorl rounded at the base, which occupies two thirds of the total shell length. Aperture whitish rather broadly ovate, columella arcuate. Columellar margin  6G). Pulmonary cavity short, occupying only the body whorl ( Fig. 6B). Kidney and pericardium restricted to middle and left sides, occupying ∼1/3 of pallial roof. Kidney triangular. Anus external to the pallial cavity ( Fig. 6A). Pulmonary vein running along entire pallial cavity, oblique in anterior 1/2, running along right edge in remaining 1/2 of pallial roof and bifurcating in the last 1/7 of the right edge ( Fig. 6G). Venation very well marked in the right edge of the of pallial roof (Figs. 6A; 6C), between the pulmonary vein and the ureter, and in a restrict part of the right side of the pulmonary vein in remaining 1/2 of the pallial roof, forming a band visible near the suture between the body whorl and the penultimate whorl (Fig. 6B). Venation imperceptible in the other parts of the pallial roof (Fig. 6G). Pericardium located at columellar margin of posterior end of pallial cavity, with approximately the same length as the kidney. Auricle elongate, smaller than the triangular ventricle. Kidney and pericardium occupying ∼1/3 of pulmonary cavity. Kidney with ∼7 lobes, with a slightly longer anterior lobe at the level of the auricle. Pulmonary vein converging to pneumostome region along with renal tube and rectum (Figs. 6A, 6B; 6G). Visceral mass (Fig. 6A). Digestive gland brownish, located along inferior region of penultimate visceral whorl, and filling entire visceral whorls anterior to stomach, including , occupying only the body whorl. Bursa copulatrix duct and penial complex with approximately the same length when distended (Fig. 7C). Bursa copulatrix lying at the transition between the spermoviduct and albumen gland (Fig. 7C). Bursa poorly differentiated from the distal portion of the duct. Basal portion of the duct is larger in width than the bursa (Fig. 7D). Prostate occupying the columellar surface of spermoviduct. Penial complex long, sub-cylindrical (Figs. 7A, 7C, 7C), passing under right ommatophore (Fig. 7E). Penis subcylindrical, not covered by a penial sheath. Penis-epiphallus transition undifferentiated. Insertion of the vas deferens subterminal (Figs. 7A; 7D). Flagellum present, subcylindrical, short in relation to the total length of the penial complex (Figs. 7A, 7C, 7D). Nearly 1/10 the length of the penial complex. Vagina very short. Spermatheca complex well differentiated as wide sinuous tube lying at the superior third of the albumen gland (Fig. 7C).
Remarks. Drymaeus (Mesembrinus) interpunctus was described based on specimens collected in Brazil without mention to the exact location of collecting by the author. Later, Ihering (1923) and Morretes (1949) also mentioned this species without specific locality. The new records from databases allowed to expand the known geographic distribution for this species in Brazil and South America.  provided a detailed anatomical description of the reproductive system from specimens from, Paraguay, and later, Miquel (1989) provided a description of the shell of one specimen from Argentina. Although the type locality of this species is in Brazil, were it presents a wide geographical distribution, the anatomy of the soft parts of specimens from Brazil was never described before. The anatomy of the reproductive system of the Brazilian specimens analyzed herein mostly corresponds to the description provided by , with the exception of the penial sheath, which was not observed in the Brazilian specimens, and also the relative length of the bursa copulatrix duct, which is nearly as long as the spermoviduct in the specimens analyzed herein, while it is about half as long as the spermoviduct in the specimens from Paraguay studied by those authors.
Remarks. Drymaeus (Mesembrinus) gereti was described for Goiás and since its description, this species was recorded in others Brazilian states . According to Wood & Gallichan (2008), the material considered as possible syntype is a specimen from ex collection of Ancey and the confirmation of its validity are a sale list and the cotype label bearing the type locality ''Goyaz''.

Drymaeus (Mesembrinus) imperfectus
Type locality: ''unkown'' (Pfeiffer, 1847 (Reeve, 1850). Mexico, (Pilsbry, 1899). In Brazil: São Paulo, Rio de Janeiro and Rio Grande do Sul states l, São Paulo, Piracicaba (Simone, 2006) (Fig. 1). Remarks. Simone (2006) figured specimens from lot 1975570 as ''possible syntypes'' from Brazil, as Mesembrinus ziegleri validating the presence of this species in Brazil. However, according to Breure & Ablett (2014), Pfeiffer would has described this species based on material from an unknown locality in northwestern Mexico. Also, they mentioned the possibility that the original material may has been lost and the label ''Brazils'' was mistrusted by Pfeiffer as he may have seen material from other sources. The analysis of material MZSP correspond to D. (M.) interpunctus and not Drymaeus (Mesembrinus) ziegleri.

DISCUSSION
In the present study, from the analysis of occurrence records of thirteen species of Drymaeus, subgenus Mesembrinus, we have confirmed the occurrence of seven species in Brazil; the records of six species, D. dominicus, D. imperfectus, D. membranaceus, D. nigrofasciatus, D. roseatus, and D. ziegleri, in both the literature and biodiversity databases being considered doubtful. The records of Drymaeus imperfectus, D. dominicus, and D. ziegleri for Brazil, obtained from malacological collections, fall outside the known distribution of these species, with huge gaps between the confirmed and the new occurrence localities. Thus, we believe that these records for Brazil most probably correspond to other species. We were able to check the images of the shells of D. imperfectus and D. dominicus specimens. However, despites the similarities in shell shape and color pattern, the significant gap between the known distribution of these species and the new records available from museum specimens justifies our decision to consider the records for Brazil as uncertain until new data from field collections is available. Interspecific similarity in shell traits between species of Drymaeus from different geographical areas is not uncommon and, in those cases, it is necessary to provide anatomical and molecular data to provide a more reliable delimitation of the species. The Colombian species D. nigrofasciatus is mentioned to occur in Brazil (Simone, 2006). However, the shell of the type specimen figured by Simone (2006) bears a disputed label according to Breure & Ablett (2014), who warned for misinterpretation. Drymaeus roseatus also considered by Simone (2006: 142) as part of the Brazilian malacofauna, was considered to occur in Amazonas state. However, the exact itinerary associated to the collections made by Wallis in ''nördlichen Südamerika'' and reported by Mousson (1869), is unknown. Wallis travelled in ''verschiedene Theile Columbias, Ecuadors und von Amazonas'' and Mousson reported the species for Amazonas, however it is unknown if this was the state of Amazonas in current understanding, or the river Amazonas. In the latter case it is unclear whether this was in Brazil, Ecuador or Colombia (ASH Breure; personal communication).
In the present study most of the species of Drymaeus, subgenus Mesembrinus, were represented in the consulted malacological collections by dry specimens ( This may indicate that these species have not been recollected over time. Alternatively, the scarcity of records obtained herein may also be a result of the deposit of specimens in local, not computerized collections, as for D. (M.) dominicus, for example, we have obtained a reasonable number of occurrence records from the literature. In any case, the absence of specimens suitable for anatomical studies in the main malacological collections worldwide, renders challenging any attempt to revisit these species to provide new morphological information. The scarcity of specimens with preserved soft parts, along with the virtual absence of recollection of live specimens also makes it difficult to compare the anatomies and to obtain DNA samples with the aim of establishing the long-needed anatomy and molecular-based operational criteria for species delimitation.  redescribed the species of Drymaeus providing new information on the anatomy of the reproductive system of species of the subgenus Mesembrinus. It is important to note that even with the available information on the anatomy of the soft parts of Drymaeus provided by previous authors (Pilsbry, 1898;Breure, 1979;, which have been demonstrated to have diagnostic value, species are still being described and synonymized based uniquely on shell morphology and color pattern. Herein . Interestingly, the better representativeness of these species in the collections is not necessarily linked to a broader geographic distribution. For example, the species D. (M.) dominicus, which is poorly represented in the consulted malacological collections, has the widest distribution amongst the species analyzed herein, occurring in seven different countries of Central America and South of North America; the occurrence records for this species being obtained mostly from the literature.
The distribution maps showing the biomes occupied by the species of the genus Drymaeus, subgenus Mesembrinus showed that all the Brazilian biomes included at least three species. Drymaeus (Mesembrinus) interpunctus is the only species present in all six Brazilian biomes, followed by D. (M.) gereti recorded in the biomes Atlantic Forest and Cerrado. Most of the records were obtained for the Atlantic Forest and Cerrado biomes, which are amongst the world's biodiversity ''hotspots'', with the highest endemism (Mittermeier et al., 2011). The Atlantic Forest, however, was exploited for centuries and only a small proportion of the original forest covering remains nowadays. Similarly, the Cerrado have recently undergone destruction by fires. Thus, species occurring in both biomes should be continuously monitored, and their conservation status accessed, with the aim of assuring their protection.
Herein, D. (M.) interpunctus was recorded for all Brazilian biomes. Interestingly, the results of niche modeling showed a thin area of high suitability to this species in South and Southeastern Brazil corresponding to the Atlantic Forest biome in the states of Rio de Janeiro, São Paulo, Paraná, and Santa Catarina; and a vast area of moderate suitability including the Atlantic Forest, Pantanal, Cerrado, and Pampa biomes. We have found two isolated records for the species in Pará state, North Brazil, corresponding to a low suitability area. We do not reject the possibility of misidentification, as we could not check the species identity of the museum specimens associated to these records. However, this result may possibly be explained by the introduction of this species outside its suitable range, as D. mesembrinus is often found in urban areas, which may facilitate its introduction by means of human activity.
Our results may indicate that D. (M.) interpunctus present a niche breadth that might favor its occurrence in a range of different biomes including less suitable areas (Sexton et al., 2017). This would partly explain the contrasting wide geographic extension of this species when compared to other Drymaeus species in Brazil. Unfortunately, there is scarce information on this and the other species of Drymaeus analyzed herein. Critical knowledge gaps are particularly concerning the ecology and life history traits of these species, for example, temperature ranges and other physical factors that Drymaeus species can tolerate, the optimal climatic conditions for their reproduction and growth, their feeding habits, the variety of food items they can eat, and the diversity of microhabitats they can inhabit. Thus, although we are not able to characterize these species in relation to the level of ecological specialization, our results on suitable areas and the potential distribution of D. (M.) interpunctus suggests that it may represent a generalist lineage. Although the number of localities compiled for the remaining species did not allow ecological niche modeling, the small number of occurrence records from the literature and the limited representation in malacological collections observed may indicate that they may have restricted ranges and they may fall into the IUCN categories of vulnerable or endangered (Breure & Vega-Luz, 2020). If the more restricted distributions of these species are a consequence of being more ecologically specialized, this may have consequences over their conservation status, considering the pressures on species to adapt in response to environmental shifts, particularly those related to climate change (Sexton et al., 2017).

CONCLUSION
1-Considering the small number of records obtained for most of the species herein analyzed, and that most of the specimens were collected several decades ago, it is probable that these species are rare. 2-The restricted ranges observed for most of the species of Drymaeus, subgenus Mesembrinus, analyzed herein, associated with historical and recent events leading to habitat destruction may indicate that they are of conservation concern, probably falling into the IUCN Categories of vulnerable or endangered. 3-The records obtained for Drymaeus (Mesembrinus) dutaillyi and Drymaeus (Mesembrinus) lynchi corresponded uniquely to type specimens, indicating the urgent need to perform field surveys to try to obtain live specimens and to access their conservation status. 4-The disparities in geographic range and occurrence records available for different species of Drymaeus, subgenus Mesembrinus in Brazil, may be associated to differences in the level of ecological specialization and climatic niche breadth, which may ultimately have consequences on their capability to respond to environmental changes. However, the low number of occurrence records available for these species impairs the development of ecological niche modeling for a greater set of taxa, pointing out the need to recollect these species and to obtain ecological information on them.

ANSP
Academy of Natural